Purification and separation of tomato isolectins by chromatofocusing

Tomato lectin can be rapidly separated from a crude extract of tomato fruit proteins by chromatofocusing. The lectin is recovered from a PBE94 column in two peaks, each with a specific activity comparable to that of lectin purified by affinity chromatography on ovomucoid-Sepharose. Both isolectins consist of a single polypeptide chain (Mr 68,000) and have similar properties.